ARM 42.26.308. APPORTIONMENT FORMULA

(1) All apportionable income of each trade or business of the taxpayer shall be apportioned to this state by use of the apportionment formula set forth in 15-31-305, MCA. The elements of the apportionment formula are the property factor (see ARM 42.26.231), the payroll factor (see ARM 42.26.241), and the receipts factor (see ARM 42.26.251) of the trade or business of the taxpayer.